Enclosure for electric motor

ABSTRACT

An enclosure comprising a first semicylindrical shell and a second semicylindrically shell juxtaposed to the first shell, the two shells being formed to fit around an object of nonuniform shape. A flexible ligamentous portion integral with both shells connects them together and acts as a hinge. One cooperating portion of a releasable lock is provided on each of the shells, one portion of the lock comprising a pair of laterally extending resilient fingers, each of the fingers having a shoulder or barb at its free end and the other a protrusion with a channel to receive the fingers. The shoulders on the fingers extend beyond the channel and hook behind it so as to prevent their inadvertent withdrawal.

United States Patent [72] Inventor Warren A. Loistrand Wethersfield,Conn.

[21 Appl. No. 16,453

[22} Filed Mar. 4, 1970 [45] Patented Nov. 23, 1971 [73] Assignee NorthAmerican Philips Corporation New York, NY.

[54] ENCLOSURE FOR ELECTRIC MOTOR Primary Examiner-D. F. DugganAssistant Examiner-B. A. Reynolds Attorney-Donald P. Gillette ABSTRACT:An enclosure comprising a first semicylindricai shell and a secondsemicylindrically shell juxtaposed to the first shell, the two shellsbeing formed to fit around anpbject oi' nonuniform shape. A flexibleligamentous portion integral with both shells connects them together andacts as a hinge. One cooperating portion of a releasable lock isprovided on each of the shells, one portion of the lock comprising apair of laterally extending resilient fingers, each of the fingershaving a shoulder or barb at its free end and the other a protrusionwith a channel to receive the fingers. The shoulders on the fingersextend beyond the channel and hook behind it so as to prevent theirinadvertent withdrawal.

PATENTEnuuv 23 IQYI 3,522 822 INVENTOR WARREN A. LOFSTRAND ATTORNEYFIELD OF THE INVENTION This invention relates to enclosures, and moreparticularly to a type of rigid enclosure to surround a device such asan electric motor and its associated gear train in order to provideprotection against dust particles and other foreign substances which maytend to interfere with the efi'icient operation of such device shouldthey be pennitted access thereto.

BACKGROUND OF THE INVENTION The invention arose out of a need for suchan enclosure with respect to, but not limited to, the gear train whichmay be associated with an electric motor. It was found that the existingenclosures were unsuitable with respect to adaptation to the particularrequirements herein described. For example, a basic one-piececylindrical enclosure made out of rigid plastic or another rigidmaterial is difficult to place in position surrounding a motor and theexposed gear train for the reason that its inflexibility results inpotential damage to the electrical leads and other connections to themotor when such an enclosure is force fitted into the proper position. Amore flexible material, which might stretch over the leads andconnections to the motor, may tend to collapse after it is emplaced,thereby exposing the gear train to dust particles and other foreignsubstances harmful to the operation of the device. A two-piece enclosureformed to avoid the electrical leads and other connections to the motorby being assembled in position on the device requires the use of aseparate hinge or hinges, with the result that such an enclosure is tooexpensive to manufacture or purchase on the market and cannot thereforebe justifiably utilized.

BRIEF DESCRIPTION OF THE INVENTION The present invention uses a pair ofsemicylindrical shell portions juxtaposed to each other around thedevice, and formed in such a way as to fit around any protrusions thatextend from the device, such as electrical leads or other connections.These shell portions are part of an integral structure joined togetherby a flexible ligamentous portion which is not a separate hinge but isreally a thin part of the material out of which the shells areconstructed. It is less expensive to mold the enclosure in such afashion than to employ a separate hinge to join the shells. A releasablelock having one cooperating portion on each of the shells is provided tosecure the enclosure around the device. The lock comprises a pair oflaterally extending resilient fingers on one shell portion and, on theother shell portion, a protrusion with a channel that is aligned withfingers when the two portions are folded together. The fingers areinserted into a channel, and barbs on the fingers extend beyond thechannel on the opposite side from insertion and hook behind it to lockthe two portions together. To release the lock, the fingers may besqueezed together, thereby moving the barbs out of contact with thecomers at the far end of the channel to allow the fingers to bewithdrawn. The barbs may also be beveled slightly to allow them to besqueezed together by lateral pressure to be forced through the channelto lock the two parts of the shell together.

One object of the present invention is to provide an enclosure whichwill effectively protect the enclosed device against dust particles andother alien substances having the tendency to interfere with efficientoperation of the device should they be permitted access thereto.

Another object of the present invention is to provide an enclosure whichmay be installed around a device without interfering with electricalleads or other parts projecting from the device.

Still another object of the present invention is to provide an enclosurewhich is simple in construction.

A further object of the present invention is to provide an enclosurewhich is inexpensive to manufacture.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of thepresent invention. reference may be had to the accompanying drawings inwhich:

FIG. 1 is an exploded view of an enclosure constructed in accordancewith the present invention and opened to receive one type of device suchas an electric motor and its gear train;

FIG. 2 is a perspective of the enclosure in position around the deviceshown in FIG. 1;

FIG. 3 is a cross-sectional view, taken along the line 3-3 in FIG. 2, ofa device enclosed by the cover in FIG. I; and

FIG. 4 is a cross-sectional view of a portion of the enclosure takenalong the line 4-4 of FIG. 3.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to thedrawings, FIG. 1 shows an enclosure according the the present inventiongenerally indicated by reference numeral 10, opened to receive a device11, such as a motor 12 and its gear train 13, which is located behind asupport plate 14. The motor is mounted on a second support plate 15,which, together with the plate 14, defines the space within which thegear train is located. It is important to note that the enclosure of thepresent invention is in no way intended to be limited to use with adevice such as that illustrated herein, and may be used with any device,the operation of which would be enhanced were it is to be protected fromdust particles and other foreign substances.

The enclosure 10 comprises a pair of semicylindrical shells l6 and 17molded of a suitable plastic material, such as polypropylene, and joinedtogether along one longitudinal edge by a flexible ligamentous portion18 which acts as a hinge and is formed out of the same plastic materialas the shells l6 and 17.

In the particular embodiment illustrated, the device 11 has a protrusion19 which supports the electrical leads 21 for the motor 12. In order toprovide a snug fit around the device 11, the enclosure 10 has notches 22and 23 located along the edges 24 and 25 of the shells l6 and 17 wherethese edges would otherwise come into contact with the protrusion 19 ofthe motor. When the enclosure is fitted into position around the device11, the juxtaposition of the notches 22 and 23 forms an opening justlarge enough to allow the protrusion 19 to extend through to insure thatthe leads will not be injured by the assembly process.

To hold the enclosure in the position illustrated in FIG. 2, anintegral, releasable lock is provided with its components dividedbetween the two shells l6 and 17. The shell I7 is provided with a pairof laterally integral fingers 26 which extend beyond the edge 24, andeach of which is provided with a shoulder, or barb, 27 and the fingersare side by side with their respective barbs facing in oppositedirections. The cooperating portion of the releasable lock is aprotrusion 28 located on the other shell 16 adjacent the edge 25.

When the enclosure 10 is fitted into position around the device 11, thefingers 23 are aligned with an opening, or channel, 29 in the protrusion28. The fingers 26 are resilient and are slightly tapered to permit themto be squeezed together in order to pass through the channel 29, andafter the barbs 27 have passed completely through the passage, thefingers spring apart and the barbs catch behind comers on the far sideof the protrusion 28. The enclosure is thus locked in place and may notbe easily inadvertently opened and removed from the device 11. However,it is possible to squeeze the ends of the fingers 26 together enough tounhook the barbs 27 from the comers at the end of the channel 29 on thefar side of the protrusion and pull the fingers back through thechannel.

The shells l6 and 17 have three internal promontories 31-33, shown inFIGS. 3 and 4. As shown in FIG. 4, these promontories are axially spacedfrom an internal shoulder 34 by a distance approximately equal to thethickness of the plate 15 for the purpose of capturing the support plate15 of the device 11 on which the motor 12 is mounted. When the enclosureis thus mounted on the device, and the support plate 15 is capturedbetween the abutment surface and the promontories, any tendency for theenclosure to move axially along the device in either direction and thusto expose any part of the device to dust particles or other foreignsubstances is reduced to a minimum. As a further aid in keeping outdust, the edge 25 has a lip 36 that fits into a recess 37 in the edge24.

What is claimed is: 1. An electric motor comprising: A. A generallycylindrical body; B. Terminal means extending from the side of saidbody; C. At least one flange at one end of said cylindrical body andextending radially therebeyond; D. A plastic enclosure surrounding saidcylindrical body and comprising:

1. first and second semicylindrical plastic shell portions,

2. a flexible hinge portion integrally formed joining contiguous edgesof said first and second semicylindrical shell portions,

3. a notch in an edge portion of said first semicylindrical shellportion diametrically opposite said flexible hinge to fit closely aroundsaid terminal; and

E. Locking means adjacent the edges of said first and secondsemicylindrical shell portions diametrically opposite said hinge to locksaid shell portions around said motor, said locking means comprising:

1. integral means defining a channel on said first semicylindrical shellportion, and resiliently deformable fingers on the other of said shellportions fitting into and locking with said means defining said channel.

2. The motor of claim 1 in which each of said semicylindrical shellportions comprises:

A. A first semicylindrical section having a diameter to fit around saidgenerally cylindrical body;

B. A second semicylindrical section of larger diameter than said firstdiameter to fit around said flange; and

C. A shoulder between said first sections and said second sections.

3. The motor of claim 2 comprising, in addition, a plurality of inwardlyextending promontories longitudinally spaced along said secondsemicylindrical sections from said shoulder by a distance at leastsubstantially equal to the thickness of said flange to capture saidflange between said promontories and said shoulder.

4. The motor of claim 2 comprising, in addition:

A. A second flange longitudinally'spaced from said firstnamed flange;and

B. Gears between said flanges forming a gearbox for said motor, thelongitudinal dimension of said second semicylindrical sections beingsubstantially equal to the overall distance between the distal faces ofsaid flanges, whereby said second semicylindrical sections comprise anenclosure for said gearbox.

1. An electric motor comprising: A. A generally cylindrical body; B.Terminal means extending from the side of said body; C. At least oneflange at one end of said cylindrical body and extending radiallytherebeyond; D. A plastic enclosure surrounding said cylindrical bodyand comprising:
 1. first and second semicylindrical plastic shellportions,
 2. a flexible hinge portion integrally formed joiningcontiguous edges of said first and second semicylindrical shellportions,
 3. a notch in an edge portion of said first semicylindricalshell portion diametrically opposite said flexible hinge to fit closelyaround said terminal; and E. Locking means adjacent the edges of saidfirst and second semicylindrical shell portions diametrically oppositesaid hinge to lock said shell portions around said motor, said lockingmeans comprising:
 1. integral means defining a channel on said firstsemicylindrical shell portion, and resiliently deformable fingers on theother of said shell portions fitting into and locking with said meansdefining said channel.
 2. a flexible hinge portion integrally formedjoining contiguous edges of said first and second semicylindrical shellportions,
 2. The motor of claim 1 in which each of said semicylindricalshell portions comprises: A. A first semicylindrical section having adiameter to fit around said generally cylindrical body; B. A secondsemicylindrical section of larger diameter than said first diameter tofit around said flange; and C. A shoulder between said first sectionsand said second sections.
 3. The motor of claim 2 comprising, inaddition, a plurality of inwardly extending promontories longitudinallyspaced along said second semicylindrical sections from said shoulder bya distance at least substantially equal to the thickness of said flangeto capture said flange between said promontories and said shoulder.
 3. anotch in an edge portion of said first semicylindrical shell portiondiametrically opposite said flexible hinge to fit closely around saidterminal; and E. Locking means adjacent the edges of said first andsecond semicylindrical shell portions diametrically opposite said hingeto lock said shell portions around said motor, said locking meanscomprising:
 4. The motor of claim 2 comprising, in addition: A. A secondflange longitudinally spaced from said first-named flange; and B. Gearsbetween said flanges forming a gearbox for said motor, the longitudinaldimension of said second semicylindrical sections being substantiallyequal to the overall distance between the distal faces of said flanges,whereby said second semicylindrical sections comprise an enclosure forsaid gearbox.